Quality of life of old people living in the community

Vol 350 • November 22, 1997 1521 reported to be expressed specifically in the brain based on northern studies, our ability to detect necdin transcripts in the liver suggests a lower, but detectable level of expression in peripheral tissues. We further examined necdin imprinting by testing expression by RT-PCR with RNA from cultured fibroblasts derived from a normal control and three patients with PWS and three with Angelman syndrome (AS), each with a documented 15q11-q13 deletion (figure B). This analysis likewise revealed imprinted expression, with necdin mRNA detectable in normal and AS samples, but not in PWS samples. The overall level of expression in cultured fibroblast cells may be quite low, given a less robust PCR product than that seen in the liver. These results show that necdin is imprinted with paternal-specific transcription in multiple tissues, including brain, which is the predominant site of its expression, and are consistent with another report indicating imprinted expression of necdin in newborn mouse brain and human fibroblasts. Necdin was initially identified as a mRNA specific to postmitotic, differentiated neuron from embryonal carcinoma cells, and found in the mouse to be expressed only in the central nervous system by northern analysis. In mouse development, necdin is expressed abundantly during periods of neural generation and differentiation, and expression is detected throughout the brain of the adult mouse, with the highest expression in the hypothalamus and midbrain. This Imprinting analysis of the human necdin gene RT-PCR on RNA from brain and liver controls and a PWS patient with a 15q11-q13 deletion (A), and RNA from cultured fibroblast cell lines from a control, three deletion PWS patients and three deletion AS patients (B). Expression of a second gene not on chromosome 15 (LDL receptor) was used as a control for RNA quality, and –RT controls are shown for necdin, whose product is colinear with genomic DNA. Details of RNA preparation and RT-PCR can be obtained from the author. Quality of life of old people living in the community